Sidewall formation sampler



May 31, 1938. M. SCHLUMBERGER SIDEWALL FORMATION SAMPLEH Filed June 16, 1957 2 Sheets-Sheet l y 1938. M. SCHLUMBERGER 2,119,361

SIDEWALL FORMATION SAMPLER Filed June 16, 1937 2 Sheets-Sheet 2 (-2 g: M f, 1 mm Patented May 31, 1938 UNITED STATES PATENT OFFICE SIDEWALL FORMATION SAMPLER France Application June 16, 1937, Serial No. 85% In France June 23, 1936 10 Claims.

Different devices for taking samples (cores), particularly in rocks traversed by a drill hole, are known, which comprise a cutting and punching instrument, constituted by a tube, the back portion of which is at least partly closed, and which is driven into the walls or the bottom of the drill hole, by the effect of a violent strain produced for instance by the firing of an explosive charge. In my U. S. A. Patent No. 2,055,- 506 of September 29th, 1936, the coring tool shot by a gun lowered in the drill holeat the end of a cable to the desired depth, is attached by a flexible connection such as a cable to the gun which has shot it, so that by exerting successively l5 tractions on the cable bearing the gun, the coring tool containing a sample of the rocks may be extracted from the formation, and brought to the surface together with the said gun. a

when, instead of samples 01' rocks, it is desired to take samples of the liquid orgas contained in the porous rocks traversed by a; drill hole (in oil sands for example), the problem becomes much more dimcult. The coring tool which is intended to contain the liquid or gas must not open until it penetrates into the porous beds, so as notto be filled with the mud contained in the drill hole. It must therefore open only under the influence of a very high pressure. Furthermore, once it has become filled with the sand containing the oil or gas it must hermetically close, since the gases in dissolution are contained in the sand under a high pressure, and they have a tendency to escape when brought to the surface and are no longer submitted to the high pressure 01 the drilling mud. There is therefore a risk of the oil disappearing more or less completely from the sample, and also of changing its chemical composition, the most volatile of the hydrocarbons being the first to be distilled as the pressure decreases while on the way to the surface. Devices are known which, in principle, give the desired result. Some of these devices comprisesimply a valve intended to open automaticallywhen the tool penetrates into the oil sand 45 bed, and then to shut by means of a spring when the coring tool has been filled with oil or gas. This arrangement is difllcult to construct, particularlybecause itis diflicult to have springs strong enough .to resist efllciently the eifect of 60 backfiring of the gun, and the pressure of the mud..*@- J 1 )1, @To remedy these conditions it, has also been proposed toplace a small plate on the front of the 1 coring tool, this plate being torn when the tool to penetrates into thesand; But in this case the device, comprising at the same time a plate and a valve, is per se relatively complicated, and furthermore presents a series of obstacles to the penetration of the sand to its inner chamber.

My present invention has for its object to prevent these drawbacks, and to ensure the absolutely satisfactory working of the coring tool. To this end, it consists in fitting the coring tool with one valve, the opposite sides of which are successively pressed against two surfaces forming its seat. The first of these surfaces, on which the head of the valve is initially pressed from outside to inside, is of a very acute truncated cone form (almost cylindrical), so that when the coring tool is projected against a porous bed of which a sample is desired, the valve, by the effect of the resistance created at the moment when the tool penetrates into the said bed, may be pushed inside the coring tool, after having been forced through its seat, thus permitting the sand and liquid and/or gas constituting the porous bed also to penetrate inside the coring tool. Then the said valve, made of sufilciently elastic material to return to its original shape, is pushed from inside towards the outside, by the eflect of an antagonistic .action provoked in any appropriate manner, so that its edges are pressed against the second supporting surface of the coring tool which forms its seat, thus ensuring hermetic closing.

The body of the coring tool being of hard steel, the valve should be made of an elastic but lighter and less hard material, such as duralumin. The valve should also be slightly funnel shaped, this firstly facilitating its passage through the front cone of the coring tool, and secondly rendering its passage in the opposite direction practically impossible, in view of the head of the valve being arched against the back cone.

A valve in the form of a ball can also be used. this ball pressing successively against both sides on the two shoulders of a throttle whose diameter is slightly smaller than that of the ball, but through which the latter is nevertheless capable of passing under the eflect of the pressure exerted on it when it, enters the sand.

According to an advantageous embodiment of my invention, the antagonistic action which ensures the closing of the valve after the coring tool has, been filled, instead of being furnished by a simple spring, is produced by the firing, of a small explosive charge. By means of this explosion, the metal itselfoi the valve which is projected against thesuriace forming its seat, is so to say in part moulded onto this surface, thus ensuring the desired hermetic closing. a q

The antagonistic strain may also be brought about by means of a spring which is compressed at the moment when the valve is forced through its seat. The explosion gases used to shoot the coring tool may also be used for this purpose, whereby these gases are enclosed in a chamber provided in this tool behind the valve stem, and the expansion force of these gases returns the valve to its second position.

Other characteristics of my invention will appear from the following description, in connection with the attached drawings, which show diagrammatically several nonlimiting examples thereof. In these drawings:

Fig. 1 is a diagrammatic section of the gun lowered in the drill hole and containing the coring tool according with my present invention.

Fig. 2 is a longitudinal section of this coring tool before the gun is fired, and Fig. 3 is a part section of this tool after'operation and taking of a sample.

Figs. 4, 5, and 6 are sections similar to Fig. 2 of three other embodiments of the invention.

On Fig. 1, I is the body of the apparatus lowered in the drill hole to the desired depth, by means of a cable 2 which contains an electric conductor 3 which is used to fire the gun, through a fuse 4 placed in the explosion chamber 5. 6 is the coring tool, the back of which fits into this explosion chamber, and which is connected by cables I and 8 for example, to the body I of the apparatus. This assembly was described in the U. S. A. Patent No. 2,055,506. When the apparatus has been lowered to the desired depth in the drill hole, and is situated for example opposite a porous bed 9, an electric current has only to be sent into conductor 2 and fuse 4, whose other extremity is earthed, to heat this fuse, cause I the explosion, and drive the coring tool 6 into the porous bed 9, where it takes the desired samples. By exerting successive tractions on the cable 2 the body I of the apparatus can be brought to the surface, having attached to it the coring tool -6 containing the desired sample.

The coring tool which constitutes the object of the present invention, and which is shown in greater detail in Figs. 2 and 3, comprises a tubular body III, carrying laterally the members II to which are attached the cables connecting it to the apparatus I. This tubular body, which has for instance the shape shown on the drawings, is

provided at its back part with an annular rubber joint I2 which ensures the tightness inside the gun, and the closing member comprises a cylindrical body It closed at its lower end by a plug II, and in which moves a piston IS. The lower part of this piston is fitted with a striker I6, details on which will be given hereafter. It is tightly attached, by screwing for example, to a valve stem II. A Joint I8 placed between this piston I5 and the bottom of stem Il ensures tightness between the inside of cylinder I3 and the inside of tube III. The bottom of valve stem I1 is fitted with a valve head I9 of the shape shown in the drawings, for example, and which is pressed by a surface I9a in the form of a truncated cone with very small angle, on a seat of corresponding form, carried by tube Ill. Furthermore, inside cylinder II and at its bottom is placed at 20 a small charge of explosive, constituted for instance by a fulminate percussion cap.

The device works in the following manner: When the explosion takes place in chamber 5, the coring tool is projected forward and first penetrates into the drilling mud. The head of valve I8, previously pressed against its seat I9, resists as long as the tool is in the drilling liquid, but as soon as it penetrates into the porous bed this valve head, under the action of the pressure exerted by the sand in the bed, is forced through its seat, and by the effect of its own elasticity firstly contracts to penetrate inside tube I0, then opens out again once it is inside the said tube.

Under the effect of the projection and the hydrostatic pressure in the drill hole, the sand containing the oil and gas penetrates inside tube III, while the assembly formed by valve I 'II 9, piston I 5 and striker I6 is pushed towards the back. The striker I6 then strikes the fulminate cap 20, and by'the effect of the explosion produced the striker and valve assembly is pushed in the opposite direction; the edges of the valve head I 9, as it is seen in Fig. 3, are then pressed against the conical part 2 of tube I0, and are to a certain degree moulded onto this conical surface, thus securing good tightness between the inside of tube III and the exterior.

In the embodiment representedon Fig. 4, the recuperating device for bringing the valve back to the position shown on Fig. 3 is constituted simply by a spring 22, which is compressed when the valve is forced through its seat, and which brings the valve back to the position shown on Fig. 3 when the tool has been filled with sand impregnated with liquid or fluid.

When this arrangement is used, it is advantageous, in accordance with my invention, to have chamber 23 containing the spring communicating directly with the explosion chamber 5 (Fig. 1) of the gun through a hole 24 for example, situated at the back of this chamber 23.

With this arrangement, the gases produced by the explosion in the powder chamber 5 penetrate into this chamber 23 and exert their pressure on piston I5, thus preventing valve I9 from being forced through its seat and pushed inside the coring tool when the shot is fired, under the effect of the force of inertia and the pressure of the liquid contained in the drill hole, as might possibly happen with the device shown on Fig. 2. The section of the piston is furthermore chosen in function of the weight of the valve and of the pressure brought to bear on it, so that this valve nevertheless remains pressed against its seat when the shot is fired, without having a tendency to be pushed forward in relation to the body of the apparatus.

The device shown on Figure 5 is similar to the foregoing, but the recuperating strain for bringing the valve back to the position of Fig. 3 is no more obtained by means of the spring 22, but by the expansion action itself of the explosion gases filling chamber 23. To this end a valve 25 (a ball valve for instance) is fitted to the back of this chamber, and maintained in normal position by a light spring 25.

When the shot is fired, the explosion gases penetrate into chamber 23 by the hole 24 and the ball 25' which immediately after presses against its seat and shuts these gases inside chamber 23.

When the valve I 9 is forced through its seat, piston I5 compresses the gases contained in chamber 23, which gases thus compressed afterwards drive the valve back to the position shown on Fig. 3.

- In the embodiment shown on Fig. 6, the valve for closing the coring tool is constituted by a ball 21 preferably of a light and elastic metal such as aluminium, for example. 0n the other hand the coring tool is provided with a throttle 28, whose diameter at this point is slightly smaller than the diameter of ball 21. The latter, when the shot is fired, is pressed against its front seat 28, as is shown in dot and dash line allowing the sand and fiuid which it containsto enter; then when container 5 is full of fluid, under the effect of an antagonistic force the ball is pushed forward again and presses against the back of the throttle, in the position indicated by the heavy line on the figure, thus ensuring the hermetic closing of container 5.

The antagonistic device for driving the ball back to this position may be of any type and particularly comprise an explosion system as is the case of Fig. 2. On the figure it has been shown, as in the case of Fig. 4, in the form of a spring 22, which is compressed when the ball penetrates into container 5, and expands again,

pushing back the ball by means of push stem 30.

Numerous modifications may naturally be applied to the device just described without going beyond the scope of the invention. In particular, the device used to drive the coring tool into the porous bed may be of any type.

What I claim is:

1. Sample taker for taking samples in formations containing a fluid comprising a container adapted to be driven into the ground where it is desired to take the sample, a valve seat placed at the front of this container, a valve normally pressed against this seat and which can be forced through its seat and pushed inside the container when the latter penetrates into the bed where it is desired to take a sample, a second seat for the valve arranged inside the container and means for pressing the valvev in the opposite direction against this second seat after the sample has been taken.

2. Sample taker for taking samples in formations containing a fluid comprising a container adapted to be driven into the ground where it is desired to take the sample, a valve seat placed at the front of this container, a valve of a truncated cone form, the inside of which is funnel shaped, normally pressed against this seat and which can be forced through its seat and pushed inside the container when the latter penetrates into the bed where it is desired to take a sample, a second seat for the valve arranged inside the container and means for pressing the valve in the opposite direction against this second seat after the sample has been taken.

3. Sample taker for taking samples in formations containing a fluid comprising a container adapted to be driven into the ground where it is desired to take the sample, a valve seat placed at the front of this container, a valve normally pressed against this seat and which can be forced through its seat and pushed inside the container when the latter penetrates into the bed where it is desired to take a sample, means for guiding the movement of the valve as it is being pushed inside the container and during its movement in the. opposite direction, a second seat for the valve arranged inside the container and means for pressing the valve in the opposite direction against this second seat after the sample has been taken.

4. Sample taker for taking samples in formations containing a fluid comprising a container adapted to be driven into the ground where it is desired to take the sample, a valve seat placed on the front of this container, a valve normally pressed against this seat and which can be forced through its seat and pushed inside the container when the latter penetrates into the bed where it is desired to take a sample, a second seat for the valve arranged inside the container and means actuated by the effect of an explosive charge for pressing the valve in the opposite direction against this second seat after the sample has been taken. a

5. Sample taker for taking samples in formations containing a fluid comprising a container adapted to be driven into the ground where it is desired to take the sample, a valve seat placed at the front of this container, a valve normally pressed against this seat and which can be forced through its seat and pushed inside the container when the latter penetrates into the bed where it is desired to take a sample, a second seat for the valve arranged inside the container, a valve stem in the shape of a piston integral with the valve, a cavity in which this stem may slide when the valve is pushed inside the sample taker, an explosive charge placed in this cavity, a striker integral with the valve stem, this striker striking and firing the explosive charge when the valve is forced through its seat and pushed inside the sample taker, the effect of this explosion being to drive the valve stem in the opposite direction and press the valve against its second seat.

6. Sample taker for taking samples in formations containing a fluid comprising a container which can be driven into the formation of which it is desired to take a sample, a throttle at the front of this container and a ball of slightly larger diameter than the inside diameter of the throttle resting normally on the outside shoulder of this throttle, and which can be forced inside the container through the throttle when the apparatus penetrates into the bed where it is desired to take a sample, and means for sending back the ball in the opposite direction against the inside shoulder of the throttle after the sample has been taken.

'7. Sample taker for taking samples in formations containing a fluid comprising a container which can be driven into the formation of which it is desired to take a sample, a throttle at the front of this container, and a ball of light and elastic metal of slightly larger diameter than the inside diameter of the throttle resting normally on the outside shoulder of this throttle, and which can be forced inside the container through the throttle when the apparatus penetrates into the bed where it is desired to take a sample, and means for sending back the ball in the opposite direction against the inside shoulder of the throttle after the sample has been taken.

8. Sample taker for taking samples in formations containing a fluid comprising a container adapted to be driven into the ground where it is desired to take the sample, a valve seat placed at the front of this container, a valve normally pressed against this seat and which can be forcedvalve arranged inside the container and a spring for pressing the valve in the opposite direction against this second seat after the sample has been taken.

9. Sample taker for taking samples in formations containing a fluid comprising a container adapted to be driven intothe ground where it is desired to take the sample, a valve seat placed at the front of this container, a valve normally pressed against this seat and which can be forced through its seat and pushed inside the container when the latter penetrates into the bed where it is desired to take a sample, means for at least partially compensating for the effort against the valve when the shot is fired so as to prevent it from being prematurely forced through its seat,

a second seat for the valve arranged inside the container and means for pressing the valve in the opposite direction against this second seat after the sample has been taken.

10. Sample taker for taking samples in formations containing a fluid comprising a container adapted to be driven into the ground where it is desired to take the sample, a valve seat placed at the front of this container, a valve normally pressed against this seat and which can be forced through its seat and pushed inside the container when the latter penetrates into the bed where it is desired to take a sample, a second seat for the valve arranged inside the container and means for pressing the valve in the opposite direction against this second seat after the sample has been taken, these means coming into action by means of the compression of the gas due to the explosion which fired the shot.

MARCEL SCHIMMIBERGER. 

